Evaporator



March 5, 1929. F. w. SIEVER'i' EvAPoRATon Filed y 15. 1926 2 Sheets-Sheet Mamh 5 F. W. SIEVERT EVAPORATOR Filed May 15. 1.926 2 Sheets-Sheet Patented Mar. 5, 1929.

I UNITED STATES PATENT/OFFICE.

nvAronA'ron.

Application filed May 15, 1926. Serial No. 109,424.

My invention relates broadly to evaporators and more particularly to a means for removing scale from the heating unit of such apparatus.

. In the operation of avaporators of the typ now in general use, it is'necessary to remove the heating unit at frequent periods that the scale deposits thereon may be removed.

It is an object of my invention toprovide a means of mechanically removing scale accumulation on the heating unit of an evaporator without the necessity of removing the unit from the evaporator shell.

Another object of my invention is to remove the scale from the heating unit of an evaporator shell while it is wet and soft.

A further object of my invention is to re= movescale from the heating unit in a quick and economical manner'and without danger of injury to the tubes of the heating unit.

With the above and other objects in view the invention consists in the construction, combination and arrangement of parts as will be hereinafter more fully described.

Reference is to be had to the accompanying drawings in which like reference characters indicate corresponding parts throughout the several views and in which:

a Figure 1 is a longitudinal sectional view through a heating unit of an evaporator, Figure 2 is an end view of Figure 1 partly in section and partly broken away, and

Figure 3 is an enlarged detail view of the roller arrangement by which the heating unit is placed in and removed from operative position.

Referring more particularly to the drawings, 5 indicates the outer wall or casing of an evaporator within which is rotatively mount ed a drum 6 having a perforated cylindrical wall I and through which extend a plurality of tubes 8. The ends of the drum are provided with a double wall 9 and 10 forming a chamber 11 therebetween. llhe drum is supported by and revolves with two hollow shafts 12 and 13 that are supported by roller bearings 1%.. Because of the heat to which. the bearings are subjected, it has been found that this type is essential over the common journal hearing. The hollow shafts pass through the casing Leakage along these shafts is prevented by any usual type of stufing boxes 15, while the connection of the shaft 12 with a stationary steam inlet pipe 16 is protected by a steam gland 17 having a white metal or bronze ring 18- to seal the point of connection.

Steam enters through inlet pipe 16 and shaft 12 to the tubes 8 and is deflected by a bafile 19 supported by the outer wall 9 of the live steam end of the drum. Condensation from the steam settles in the chamber 11 whence it is driven out through drain pipe 20 by the steam pressure in the steam line 16. The drain pipe extends through the hollow shaft 13 and is so positioned that the portion within the chamber is at all times in a vertical plane irrespective of the rotation of the drum.

Motion is imparted to the drum by a motor (not shown) through a shaft 21 connected therewith and carrying a worm gear- 22 that enga es with gear 23 keyed or otherwise remova ly secured to the hollow shaft 12.

Water or the fluid to be evaporated is fed through pipe 26 to a pipe 28 that is slotted on its lower slde and that forms a hood 27 extending over the width of the drum. The water continues in its flow through the perforations in the drum wall where it is vaporized by the heat supplied to the tubes 8. The vapor produced is permitted to escape into a chamber 41 and then through a perforated drum 36 and an outlet 37 and is condensed by any type of condenser. The hood 27 is curved to engage with the cylindrical wall 7 and fits over it'W ltl'l just enough clearance at its ends to prevent rubbing when the drum is rotated thus preventing escape of water over the surface of the drum but instead directing the water through the perforations along the top of the drum. j

The portion of the incoming fluid that is not evaporated, together with the scale that has been removed, passes through the perforations in the lower wall of the drum to be carried 0d as waste.

While the drum is in operative position it is supported by the hollow shafts. lf it is necessary to remove it from the casing to efiect repairs, rollers 29 are inserted through the holes 30, and secured to the drum as shown in Figure 1. The rollers turn on axles 31 that are supported by frames 32 which frames are secured to upright members 3t by pivot joints 33. Notches on the upright members 34 engage with hooks 35 secured to the outer wall 9 of the drum ends. When placed in such a position adjusting elements are regulated to cause the frames 32 to pivot about the joints 33 whereby the rollers 29 engage with track 38 and support the weight of the drum. The drum may be withdrawn from the casing on an extended track (not shown), of any common construction. drum while it is in the casing to permit the drum to turn, and also to prevent the rollers from becoming clogged by the scale loosened from the drum and tubes. It has been found that the drum need be rotated but once a day and then for only about 10 to 15 minutes to insure that the tubes are clean and free from scale and therefore in their most efficient condition.

The scale is removed from the tubes 8 and from the interior of the drum by a plurality of brass or bronze hexagonal pellets 24 that are free to tumble about within the drum. As the drum is rotated by shaft 21 and gears 22 and 23, the pellets are carried upward by angle bars 25 secured to the inner surface of the cylindrical wall. As the angle bars up proach the upper part of their circular path,

the pellets will-drop to the bottom of the drum to be againcarried upward and in falling they strike against the tubes knocking off such scale as may have lodged thereon. The scale thus freed is washed through the perforations in the wall and through discharge passageways at 39. As the scale is wet and soft and consequentlyeasy to loosen and because the simplicity of operation of the device makes it possible to remove scale daily, only a thin layer will accumulate and therefore the dropping of the pellets need not be great thuseliminating the injurious effect on the tubes when the thickness of the scale requires the use of a chipping hammer.

It will be understood that the above de scription and accompanying drawings comprehend onl the general and preferred embodiment o my invention and that minor details in construction, and arrangement of parts may be made within the sco appended claims and without sacri cing any of the advantages of my invention.

Having thus described my invention what I claim is:

1. In an evaporator, a rotary perforated drum, heating tubes extending therethrough, means for conducting a heatin fluid to the tubes, means for passing a liquid to be evaporated through the perforations onto the tubes, means operative during the rotation The rollers are removed from the e of the of the drum for removing solids deposited on the tubes and the interior of the drum by the said liquid, and means for removing the residue of the liquid after passing throughthe drum.

2. In an evaporator, a rotar perforated drum, heating elements exten ing between the heads of the drum, means for conducting heat to the elements, means for conducting a liquid to be evaporated onto the drum for passage through the perforations onto the elements, means for removing solids deposited on the elements and the interior of the drum by the said liquid, and means for removing the residue of the liquid after passing through the drum.

3. In an evaporator, a rotary perforated drum, heating means therein, an inlet for a liquid to be evaporated, means connected therewith for spreading and directing'the liquid through the perforations, means for removing solids deposited on the heating means and drum by the liquid, and means for removing Waste material from the evaporator.

4. In an evaporator, a rotary drum having a perforated wall, heating means therein, an inlet pipe for a liquid to be evaporated, a slotted nozzle connected thereto means carried by the nozzle for retarding flow of the liquid over the sides of the drum and di recting it through the perforations, means Within the drum for removing solids deposited on the heating means and drum by the liquid, and means for removing waste from the evaporator.

5. An evaporator including a casing, a drum rotatable within the casing and removed therefrom, means for rotating the drum, heating means in the drum, means for conductin a heating fluid to the heating means, a fiiamber on either side of the drum with which the heating means communicate,

' means in the chamber on the inlet side of the drum for diffusing the heating fluid to all of the heating means, means in the chamber on the outlet of the drum for carrying off the spent heating fluid, means for directing a liquid to be evaporated to the drum, means for removing the evaporated liquid, and means for removing waste material.

F. W. SIEVERT, U. s; N. 

